This section is intended to introduce various aspects of the art, which may be associated with exemplary embodiments of the present invention. This discussion is believed to assist in providing a framework to facilitate a better understanding of particular aspects of the present invention. Accordingly, it should be understood that this section should be read in this light, and not necessarily as admissions of any prior art.
As the world's petroleum supplies continue to diminish there is a growing need for alternative materials that can be substituted for various petroleum products, particularly transportation fuels. A significant amount of effort has been placed on developing new methods and systems for providing energy from resources other than fossil fuels. Currently, much effort is underway to produce bioethanol and other transportation fuels and chemicals from renewable biomass materials. One type of biomass is plant biomass, which contains a high amount of carbohydrates including sugars, starches, celluloses, lignocelluloses, hemicelluloses. Efforts have particularly been focused on ethanol from fermentable sugar readily available and ethanol from cellulosic materials.
Conventional ethanol production from corn typically competes with valuable food resources, which can be further amplified by increasingly more severe climate conditions, such as droughts and floods, which negatively impact the amount of crop harvested every year. The competition from conventional ethanol production can drive up food prices. While other crops have served as the biomass material for ethanol production, they usually are not suitable for global implementations due to the climate requirements of such crops. For instance, ethanol can also be efficiently produced from sugar cane, but only in certain areas of the world, such as Brazil, that have a climate that can support near-year-round harvest.
Further, additional fermentable sugars can be freed from lignocellulosic biomass, which comprises hemicelluloses, cellulose and smaller portions of lignin and protein. Cellulose comprises sugars that can be converted into fuels and valuable chemicals, when they are liberated from the cell walls and polymers that contain them.
Current processes aiming to process lignocellulosic biomass are limited to feedstock that includes unprocessed biomass materials or municipal solid waste (MSW). Unprocessed biomass includes sugarcane bagasse, forest resources, crop residue, and wet/dry harvested energy crops. These conventional feedstock sources require storage, transportation, particle size reduction, and additional front end processing before they can be introduced for further processing of lignocellulosic material. For example, baling of biomass is costly and can result in hazards such as fire, rodent, dust, unwanted debris (such as rocks) and hantavirus. Further, bales and forest resources are more costly to transport than denser material and more costly to handle than materials that are already particle size reduced and do not need to be further formatted. MSW further has challenges related to contamination with regulated hazardous metals that can contribute to risks of poor fuel quality as well as health and safety risks. Forest resources, such as trees, are cumbersome to transport. Further, forest resources require debarking, chopping to wood chips of desirable thickness, and washing to remove any residual soil, dirt and the like. Therefore, there is still a need for a biomass that addresses these challenges.